<p>laforge <strong>merged</strong> this change.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bts/+/15656">View Change</a></p><div style="white-space:pre-wrap">Approvals:
laforge: Looks good to me, approved
pespin: Looks good to me, but someone else must approve
Jenkins Builder: Verified
</div><pre style="font-family: monospace,monospace; white-space: pre-wrap;">scheduler: fix handling of PTCCH/U and PTCCH/D logical channels<br><br>According to 3GPP TS 45.010, section 5.6.2, for packet-switched<br>channels the BTS shall monitor the delay of the Access Bursts<br>sent by the MS on PTCCH and respond with timing advance values<br>for all MS performing the procedure on that PDCH.<br><br>According to 3GPP TS 45.002, section 3.3.4.2, PTCCH (Packet Timing<br>advance control channel) is a packet dedicated channel, that is<br>used for continuous Timing Advance control (mentioned above).<br><br>There are two sub-types of that logical channel:<br><br> - PTCCH/U (Uplink): used to transmit random Access Bursts<br> to allow estimation of the Timing Advance for one MS in<br> packet transfer mode.<br><br> - PTCCH/D (Downlink): used by the network to transmit<br> Timing Advance updates for several MS.<br><br>As per 3GPP TS 45.003, section 5.2, the coding scheme used for<br>PTCCH/U is the same as for PRACH as specified in subclause 5.3,<br>while the coding scheme used for PTCCH/D is the same as for<br>CS-1 as specified in subclause 5.1.1.<br><br>The way we used to handle both PTCCH/U and PTCCH/D is absolutely<br>wrong - they have nothing to do with xCCH coding. Instead, we<br>need to use tx_pdtch_fn() for Downlink and rx_rach_fn() for Uplink.<br><br>In l1sap_ph_rach_ind() we need to check if an Access Burst was<br>received on PTCCH/U and forward it to OsmoPCU with proper SAPI<br>value (PCU_IF_SAPI_PTCCH). To be able to specify a SAPI, a new<br>parameter is introduced to pcu_tx_rach_ind().<br><br>Change-Id: I232e5f514fbad2c51daaa59ff516004aba97c8a3<br>Related: OS#4102<br>---<br>M include/osmo-bts/pcu_if.h<br>M src/common/l1sap.c<br>M src/common/pcu_sock.c<br>M src/common/scheduler.c<br>4 files changed, 26 insertions(+), 8 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/include/osmo-bts/pcu_if.h b/include/osmo-bts/pcu_if.h</span><br><span>index 114f87d..f34e0cd 100644</span><br><span>--- a/include/osmo-bts/pcu_if.h</span><br><span>+++ b/include/osmo-bts/pcu_if.h</span><br><span>@@ -12,7 +12,7 @@</span><br><span> uint16_t arfcn, uint8_t block_nr, uint8_t *data, uint8_t len,</span><br><span> int8_t rssi, uint16_t ber10k, int16_t bto, int16_t lqual);</span><br><span> int pcu_tx_rach_ind(struct gsm_bts *bts, int16_t qta, uint16_t ra, uint32_t fn,</span><br><span style="color: hsl(0, 100%, 40%);">- uint8_t is_11bit, enum ph_burst_type burst_type);</span><br><span style="color: hsl(120, 100%, 40%);">+ uint8_t is_11bit, enum ph_burst_type burst_type, uint8_t sapi);</span><br><span> int pcu_tx_time_ind(uint32_t fn);</span><br><span> int pcu_tx_pag_req(const uint8_t *identity_lv, uint8_t chan_needed);</span><br><span> int pcu_tx_pch_data_cnf(uint32_t fn, uint8_t *data, uint8_t len);</span><br><span>diff --git a/src/common/l1sap.c b/src/common/l1sap.c</span><br><span>index a77b53a..2874c81 100644</span><br><span>--- a/src/common/l1sap.c</span><br><span>+++ b/src/common/l1sap.c</span><br><span>@@ -1313,6 +1313,20 @@</span><br><span> </span><br><span> DEBUGPFN(DL1P, rach_ind->fn, "Rx PH-RA.ind\n");</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ /* PTCCH/UL (Packet Timing Advance Control Channel) */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (L1SAP_IS_CHAN_PDCH(rach_ind->chan_nr) && L1SAP_IS_PTCCH(rach_ind->fn)) {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGPFN(DL1P, LOGL_DEBUG, rach_ind->fn,</span><br><span style="color: hsl(120, 100%, 40%);">+ /* TODO: calculate and print Timing Advance Index */</span><br><span style="color: hsl(120, 100%, 40%);">+ "Access Burst for continuous Timing Advance control (toa256=%d)\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ rach_ind->acc_delay_256bits);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* QTA: Timing Advance in units of 1/4 of a symbol */</span><br><span style="color: hsl(120, 100%, 40%);">+ pcu_tx_rach_ind(bts, rach_ind->acc_delay_256bits >> 6,</span><br><span style="color: hsl(120, 100%, 40%);">+ rach_ind->ra, rach_ind->fn, rach_ind->is_11bit,</span><br><span style="color: hsl(120, 100%, 40%);">+ rach_ind->burst_type, PCU_IF_SAPI_PTCCH);</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* check for handover access burst on dedicated channels */</span><br><span> if (!L1SAP_IS_CHAN_RACH(rach_ind->chan_nr)) {</span><br><span> rate_ctr_inc2(trx->bts->ctrs, BTS_CTR_RACH_HO);</span><br><span>@@ -1349,8 +1363,8 @@</span><br><span> rach_ind->acc_delay, rach_ind->ra);</span><br><span> </span><br><span> pcu_tx_rach_ind(bts, rach_ind->acc_delay << 2,</span><br><span style="color: hsl(0, 100%, 40%);">- rach_ind->ra, rach_ind->fn,</span><br><span style="color: hsl(0, 100%, 40%);">- rach_ind->is_11bit, rach_ind->burst_type);</span><br><span style="color: hsl(120, 100%, 40%);">+ rach_ind->ra, rach_ind->fn, rach_ind->is_11bit,</span><br><span style="color: hsl(120, 100%, 40%);">+ rach_ind->burst_type, PCU_IF_SAPI_RACH);</span><br><span> return 0;</span><br><span> }</span><br><span> </span><br><span>diff --git a/src/common/pcu_sock.c b/src/common/pcu_sock.c</span><br><span>index ba9e172..51f72d8 100644</span><br><span>--- a/src/common/pcu_sock.c</span><br><span>+++ b/src/common/pcu_sock.c</span><br><span>@@ -380,7 +380,7 @@</span><br><span> }</span><br><span> </span><br><span> int pcu_tx_rach_ind(struct gsm_bts *bts, int16_t qta, uint16_t ra, uint32_t fn,</span><br><span style="color: hsl(0, 100%, 40%);">- uint8_t is_11bit, enum ph_burst_type burst_type)</span><br><span style="color: hsl(120, 100%, 40%);">+ uint8_t is_11bit, enum ph_burst_type burst_type, uint8_t sapi)</span><br><span> {</span><br><span> struct msgb *msg;</span><br><span> struct gsm_pcu_if *pcu_prim;</span><br><span>@@ -395,7 +395,7 @@</span><br><span> pcu_prim = (struct gsm_pcu_if *) msg->data;</span><br><span> rach_ind = &pcu_prim->u.rach_ind;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- rach_ind->sapi = PCU_IF_SAPI_RACH;</span><br><span style="color: hsl(120, 100%, 40%);">+ rach_ind->sapi = sapi;</span><br><span> rach_ind->ra = ra;</span><br><span> rach_ind->qta = qta;</span><br><span> rach_ind->fn = fn;</span><br><span>diff --git a/src/common/scheduler.c b/src/common/scheduler.c</span><br><span>index 40e0a54..19fec32 100644</span><br><span>--- a/src/common/scheduler.c</span><br><span>+++ b/src/common/scheduler.c</span><br><span>@@ -539,11 +539,15 @@</span><br><span> .desc = "Packet Timing advance control channel",</span><br><span> .chan_nr = RSL_CHAN_OSMO_PDCH,</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* Same as for TRXC_BCCH (xCCH), see above. */</span><br><span style="color: hsl(120, 100%, 40%);">+ /* On the Uplink, mobile stations transmit random Access Bursts</span><br><span style="color: hsl(120, 100%, 40%);">+ * to allow estimation of the timing advance for one MS in packet</span><br><span style="color: hsl(120, 100%, 40%);">+ * transfer mode. On Downlink, the network sends timing advance</span><br><span style="color: hsl(120, 100%, 40%);">+ * updates for several mobile stations. The coding scheme used</span><br><span style="color: hsl(120, 100%, 40%);">+ * for PTCCH/D messages is the same as for PDTCH CS-1. */</span><br><span> .flags = TRX_CHAN_FLAG_PDCH,</span><br><span> .rts_fn = rts_data_fn,</span><br><span style="color: hsl(0, 100%, 40%);">- .dl_fn = tx_data_fn,</span><br><span style="color: hsl(0, 100%, 40%);">- .ul_fn = rx_data_fn,</span><br><span style="color: hsl(120, 100%, 40%);">+ .dl_fn = tx_pdtch_fn,</span><br><span style="color: hsl(120, 100%, 40%);">+ .ul_fn = rx_rach_fn,</span><br><span> },</span><br><span> [TRXC_CBCH] = {</span><br><span> /* TODO: distinguish CBCH on SDCCH/4 and SDCCH/8 */</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bts/+/15656">change 15656</a>. 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<div style="display:none"> Gerrit-Project: osmo-bts </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I232e5f514fbad2c51daaa59ff516004aba97c8a3 </div>
<div style="display:none"> Gerrit-Change-Number: 15656 </div>
<div style="display:none"> Gerrit-PatchSet: 2 </div>
<div style="display:none"> Gerrit-Owner: fixeria <axilirator@gmail.com> </div>
<div style="display:none"> Gerrit-Reviewer: Jenkins Builder </div>
<div style="display:none"> Gerrit-Reviewer: fixeria <axilirator@gmail.com> </div>
<div style="display:none"> Gerrit-Reviewer: laforge <laforge@osmocom.org> </div>
<div style="display:none"> Gerrit-Reviewer: lynxis lazus <lynxis@fe80.eu> </div>
<div style="display:none"> Gerrit-Reviewer: pespin <pespin@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: merged </div>